American Mink

American Mink

Neovisin Vison. By Dennis C. Joyes

This story is featured in Montana Outdoors September-October issue

When I was a boy, a friend decided to go into the trapping business. Muskrat pelts were selling for $3 apiece, and he was convinced there was a fortune to be made. Not much came of his venture. But I do remember that his first catch was not a muskrat but a dark brown weasel-like animal our parents later identified as a mink. We had never seen such an animal up close and were intrigued by its graceful shape, partially webbed feet, and luxurious, chocolate-brown fur. Many years later, I remain fascinated by this small, sleek predator, which I see once in a while loping along stream- or riverbanks.

Mink belong to the weasel, or mustelid, family. Like weasels, they have a long, slim body, but are stouter and weigh two to three times as much as most weasels. Adult male mink are about two feet long, including the seven-inch tail, and weigh roughly two pounds. Females weigh half that and are about 18 inches long. A mink’s ears are short and barely visible. Its feet are fully furred, with toes webbed near the base. Unlike weasels, mink do not change color with the seasons, remaining dark brown, with a white patch on the chin and parts of the throat, year round. The soft fur, with its dense underlayer and glistening guard hairs, has long been valued for coats, stoles, and jacket trim.

Mink live throughout Montana and across the United States and Canada except in the Arctic and the desert Southwest.

Mink love water. They live in wetlands and along the shores of lakes, rivers, and streams. They hunt in shallows and den in abandoned muskrat dens along banks, beneath piles of brush or driftwood, and in hollow logs. In Montana, mink are found from the mountainous forests along the Idaho border to the state’s eastern prairies and even semi-desert, as long as water is nearby.

Food and Hunting
Mink are strictly meat eaters that hunt alone and mainly at night. A mink has a home range of roughly three square miles, though biologists have tracked some radio-collared individuals as far as seven miles in a single night. Strong swimmers, mink cruise below the water surface hunting fish, frogs, and crayfish. Mink also hunt muskrats, mice, and voles. In prairie wetlands, ducks make up a large share of a mink’s diet. The small predator will eat the eggs and kill ducklings and even an adult hen on its nest.

Mink usually mate in March. Females often mate with a second male about a week after the first mating, producing a single litter with offspring from both males. Baby mink are usually born after about 40 days gestation in April or early May. If a female mates early, in February, she may delay embryonic development for up to a month so that the young are born later in spring when prey is more abundant. The three to five kits are born blind and covered with a coat of silvery white hair. They are weaned at five weeks and begin to hunt on their own within two to three months. By the following February, mink are sexually mature. Mink can live for eight years in captivity, but only one to three years, on average, in the wild. Owls, hawks, foxes, coyotes, and large snakes prey on mink, especially the young.

Conservation Status
Because mink hunt mainly at night or at dawn and dusk, people rarely see them in the wild. Yet mink are abundant throughout their range. Though mink are still legally trapped during the winter, commercial mink farms produce most pelts, mainly sold in Europe and Asia.  

Scientific name
Vison is an Icelandic or Swedish word for “marten” or “weasel.” Neo means “new” or “revived form.” The common name, mink, may come from the Swedish word for the species, maenk.Bear bullet

Writer Dennis C. Joyes lives in Ontario and frequently visits his home state of Montana.